Improvement in boiler-coverings



2SheetsSheet1. F. B. STEVENS.

v BOILERWUVERING; No.169,492, Patented Nov. 2,18%.

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i I i i WITNESSES iikvww INVENTOR I W N-PETES. FNOTO UTHDGRAPHERWASHINGTON, D. C.

UNITED S'rn'rns Penna-r Qr'rron.

FRANCIS B. STEVENS, OF HOBOKEN, NEW JERSEY.

IMPROVEMENT IN BOILER-COVERiNGS.

Specification forming part of Letters Patent N 0. 169,492, datedNovember 2, 1875; application filed August 9, 1875.

To all whom it may concern:

Be it known that I, FRANCIS B. STEVENS, of Hoboken, Hudson county, NewJersey, have invented an Improvement in Covering Boilers and HeatedSurfaces, of which the following is a specification:

My invention consists in covering boilers and other heated surfaces witha number of hollow metallic sections, each hollow section being formedof a sheet of metal next to the boiler, an outer sheet, and side sheetsjoining the inner and outer sheets, and forming the sides or edges ofthe hollow metallic section.

. The cavity in these sections can be filled with ,i any non-conductingsubstance, or it can be eft unfilled, so that the confined stratum ofair may alone act as the non-conducting material. I attach these hollowsections to the boiler or surface to be covered by standingbolts securedto the boiler or, in circular boilers, I can attach them by bandsencircling the boiler, and placed over the junction of contiguoussections, in the manner that the sheet-iron covering is secured tolocomotive and other boilers by bands. My invention also consists inmaking projecting pieces or flanges of sheet metalaround the sides ofthe inner surface of the hollow sections, so that these sections mayonly touch the boiler at the edges of these sheet-metal projections. Bythis means less heat will be communicated from the boiler to the hollowsections, for a stratum of air will intervene, and the edges of thesheet-metal projections that form the only points of contact can conveybut little heat from the boiler to hollow sections. By this means, also,the projecting pieces can be readily fitted over the laps andrivet-heads of the boiler, in the same way that wooden circles orsegments are cut and fitted around circular boilers covered withsheetiron, and the hollow sections may be made to present an evensurface on the outside.

Figure 1 is a horizontal view of a hollow section on a scale of fourinches to the foot. Fig. 2 is a crosssection taken through the dottedline as m of Fig. l. i

A is the piece of sheet metal that forms the inner surface of the hollowsection. B is the sheet metal that forms the outer surface of the hollowsection. 0 is the sheet metal that forms the edges of the hollowsections. The

sheets A and B are shown one inch and threequarters apart, thus leavingthe cavity D of that width. E E E E are the projecting edges of sheetmetal around the sides or edges of the hollow sections. F is astanding-bolt, by which the hollow section can be screwed to the boilerand held there securely. o 0 are. rivet'heads between the inner surfaceof the hollow section and the surface of the boiler.

Fig. 3 is a portion of a section of a boiler, showing parts of twohollow metallic sections and their junction near a lap of twosheets ofthe boiler. The etched surface E of Fig. 3 shows the pieces ofsheet-metal projecting beyond the inner sheetA of the hollow sections,and fitted over the rivet-head 0 and lap n of the boiler. Without theprojecting piece E the hollow section shown at the right hand of Fig. 3would rest on the boiler, as shown by the dotted lines, while thesection to the left hand would rest on the rivet-head.

Fig. 4 is a portion of a flat surface of a boiler covered with a numberof hollow secsections, B B B, showing the outer sheets of each of thesesections, and F F F showing screw-bolts, one in the center of eachsection,

to fasten it to the boiler.

The sheet metal can be put together to form the hollow sections byrivets or any of the methods commonly employed to fasten together sheetsof metal.

I am aware of the application of tiles (of porcelain or other material)to heated surfaces; and I do not claim the application of tin plates orother thin sheet metal as an inner lining-surface for the non-conductingor porous covering of boilers or steam-pipes; and I do not claimcovering a steam boiler, pipe, or other heater with any non-conductingmaterial when the latter is supported by a framework removed from andsurrounding the former, not being in direct contact, but having anintervening air-space.

I claim as my invention in boiler-covermg 1. The hollow sections ofmetal formed by the inner sheet of metal A, the outer sheet of metal B,and the side sheets of metalO O.

2. The hollow sections of metal formed by the inner sheet of metal A,the outer sheet of metal B, and the side sheets of metal 0 O, incombination with the inner projecting flanges E E, as and for thepurpose specified.

FRANCIS B. STEVENS.

Witnesses L. W. BROWN, R. GoFFIN.

